CsxWO3 films with excellent infrared shielding ability and high visible light transmittance prepared via magnetron sputtering

Caesium tungsten bronze materials are widely used in various applications, such as architectural glass, medicine, insulation coating and textile fibre, owing to their excellent mechanical, optical and thermal properties. In this study, a caesium tungsten bronze (CsxWO3, x = 0.3-0.32) target with a relative density of 99.63 % and uniform microstructure was successfully prepared via hot-pressing sintering. CsxWO3 films were deposited on a quartz glass substrate via magnetron sputtering, and the mechanisms and effects of the substrate temperature and oxygen flow rate on the phase structure, microstructure and optical properties of CsxWO3 films were investigated. When the substrate temperature increased, the crystallinity and oxygen vacancy concentration of the CsxWO3 film improved. Consequently, the visible light transmittance of the film decreased, whereas the infrared blocking rate considerably increased, reaching up to 93.877 %. With the increase in the oxygen flow rate, the visible light transmittance exhibited an increasing trend, reaching a maximum value of 84.319 %, whereas the infrared blocking rate remained relatively stable. We successfully fabricated CsxWO3 films possessing a visible light transmittance of 66 % and infrared blocking rate of 94.97 % under the conditions of a substrate temperature of 300 degrees C and an oxygen flow rate of 2.5 sccm. Our study offers a method for the large-scale production of CsxWO3 films, which are excellent infrared shielding materials, rendering a substantial contribution to global energy conservation and emission reduction.